1. The SIO Glider Program
The underwater glider ‘Spray’

2. Operations in AOSN 2003 Five gliders for 5 weeks uninterrupted
~2.5 km
Five gliders for 5 weeks uninterrupted
Operate 5 ~100-km offshore sections
Speed ~25 km/day ~0.5 knot
Profile to 400 m or 3 m from bottom
Cycle takes ~3 hours
~ 400 m
Objectives: data for model assimilation; technical development
0 to 400 m vertical average velocity interesting
T data good but need higher vertical resolution
CTD, Optical Backscatter, Fluorometer all suffer from biofouling
Scales are 25 km and 2 days, shorter than we planned for

3. 0-200m
August 2003 Glider Array
0-400m

4. Velocity – Days

5. Fouling Is The Limit to Duration
In AOSN II five Sprays operated 35 days using 20% of their battery energy
All five optical (backscatter/fluorometer) sensors failed from fouling
CTDs were erratic as a result of biofouling
Even if sensors work, fouling will eventually degrade gliding performance

6. Scales of Variability
Scales longer at surface – Offshore variation unknown
On average L ~ 25 km T ~ 2 days T L

7. MURI 2005 Preparations Test new CTD and short-range ADCP in San Diego
Improve and simplify the AOSN 2004 quality-control process and provide web access
Develop web-based software to simplify control and to guard against errors in issuing mission changes
2005 Field Trial:
Verify that bio-fouling problems under control
Gather statistical info (scales, tide energy, etc.) needed to plan 2006 experiment.
Use adaptive control to control scale-measuring array

8. MURI 2006 4 Sprays with CTD and ADCP (U(z), T(z), S(z))
Use software for 24/7 maintenance of the array to maximize mapping skill will be available (in collaboration with Princeton)
Gliders can be used to map mesoscale while investigating:
1. Mixing (Thorpe Scale) and relation to Richardson Number
2. Mixing and advection by internal tides
3. Mixed layer response to winds in upwelling
4. Accuracy of acoustic propagation predictions?